Fix setFocus() call

How to reproduce:
- press CTRL+F on main panel

Traceback (most recent call last):
  File "/home/zas/src/picard/./picard/ui/mainwindow/__init__.py", line 277, in keyPressEvent
    self.search_edit.setFocus(True)
TypeError: arguments did not match any overloaded call:
  setFocus(self): too many arguments
  setFocus(self, reason: Qt.FocusReason): argument 1 has unexpected type 'bool'


Solution:

- pass proper Qt.FocusReason; not True

picard/ui/mainwindow/__init__.py

@@ -274,7 +274,7 @@ def keyPressEvent(self, event):
             else:
                 self.remove()
         elif event.matches(QtGui.QKeySequence.StandardKey.Find):
-            self.search_edit.setFocus(True)
+            self.search_edit.setFocus(QtCore.Qt.FocusReason.ShortcutFocusReason)
         else:
             super().keyPressEvent(event)